I'm a state employed stream surveyor that monitors salmon populations through fall spawning events. My co-worker and I found these red-legged frog tadpoles on one of our surveys. You can see that some of them are starting to form legs and they're all quite healthy. They stockpile energy for short, fast spurts to get away from predators. This is why they don't go very far before they have to stop and rest. Hope you enjoy!